Pressure vessel

ABSTRACT

This invention relates to the art of pressure vessels of the type having a cylindrical container, one end of which is closed and has a port, and the other end of which defines an open mouth. The container has a deformable bladder of resilient material positioned therein, said bladder having a large mouth with an annular supporting member secured thereto and extending outwardly therefrom. The free edge portion of the supporting member which is longitudinally spaced from the region where the bladder is secured thereto, extends into an annular groove defined between the inner surface of the open mouth of the container and the outer periphery of a cover member positioned in the upper portion of the supporting member, the opposed surfaces of the annular groove and the free edge portion of the supporting member being bonded together to seal the container.

United States Patent Zahid Sept. 12, 19 72 [54] PRESSURE VESSEL [72]Inventor: Abduz Zahid, Los Angeles, Calif.

[73] Assignee: Greer Hydraulics, Inc., Los Angeles, Calif.

[22] Filed: Dec. 16, 1970 [21] Appl. No.: 98,593

[52] U.S. Cl ..138/30 [51] Int. Cl ..Fl6l 55/04 [58] Field of Search..l38/30 [56] References Cited UNITED STATES PATENTS 2,878,834 3/1959Mercier ..138/3O 3,109,458 11/1963 Mercier ..138/30 3,500,866 3/1970Greer ..1 38/30 3,138,176 6/1964 Mercier ..138/30 11/1970 Fulmer..138/30 Primary Examiner-Herbert F. Ross AttorneyArthur B. Colvin [5 7]ABSTRACT This invention relates to the art of pressure vessels of thetype having a cylindrical container, one end of which is closed and hasa port, and the other end of which defines an open mouth. The containerhas a deformable bladder of resilient material positioned therein, saidbladder having a large mouth with an annular supporting member securedthereto and extending outwardly therefrom. The free edge portion of thesupporting member which is longitudinally spaced from the region wherethe bladder is secured thereto, extends into an annular groove definedbetween the inner surface of the open mouth of the container and theouter periphery of a cover member positioned in the upper portion of thesupporting member, the opposed surfaces of the annular groove and thefree edge portion of the supporting member being bonded together to sealthe container.

1 Claim, 3 Drawing Figures PATENIEDSEP 12 m2 INVESTOR. ABDUZ ZAHIDPRESSURE VESSEL As conducive to an understanding of the invention, it isnoted that where a pressure vessel is of the type comprising a rigidcontainer with a deformable bladder therein intervening between twoports, through one of which a large amount of fluid may flow into andout of the chamber defined between the exterior of the bladder and therigid container, and through the other of which the bladder is chargedwith gas under pressure, if the bladder which is in communication withsaid last named port is not dependably secured in place or if thechamber into which the fluid flows is not dependably sealed, leakage mayoccur with resultant malfunctioning of the pressure vessel.

It is accordingly among the objects of the invention to provide apressure vessel of the above type which may readily be manufactured atrelatively low cost and which will provide for dependable retention ofthe bladder in the container with assurance that a dependable leak-proofseal will be provided to prevent leakage of gas and oil from thecontainer.

According to the invention, these objects are accomplished by thearrangement and combination of elements hereinafter described and moreparticularly recited in the claims.

In the accompanying drawings in which is shown one of various possibleembodiments of the several features of the invention,

FIG. 1 is a longitudinal cross sectional view of a pressure vessel madein accordance with the invention herein,

FIG. 2 is an enlarged detailed view showing the connection of thesupporting member to the container, and

FIG. ,3 is a fragmentary detail view illustrating a step in the assemblyof the pressure vessel.

Referring now to the drawings, the pressure vessel illustrativelycomprises a substantially cylindrical container 11, of rigid materialsuch as steel or aluminum, capable of withstanding the pressure to whichit is to be subjected in use.

The container has one end closed as at 12 and a sleeve 13 is positionedin an axial opening 14 in such closed end. As is clearly shown, theinner end 15 of the sleeve has an outwardly extending annular flange 16which rests on the periphery of opening 14, and the sleeve is secured infixed position as by welding as at 17.

The bore 18 of the sleeve 13, which defines a port through which fluidmay flow, has its inner end beveled as at 19 to define a valve seat.

Positioned in the mouth of the container 11 remote from the closed end12 thereof is a closure head or cover member 21 which illustratively hasan annular groove 22 in its undersurface defining a relatively narrowperipheral rim 23 on its undersurface and an axial hub 24 the inner end25 of which extends beyond the plane of peripheral rim 23.

The closure head 21 has an axial bore extending therethrough, theportion 26 of said bore extending through the axial hub 24 being ofsmaller diameter than the outer portion 27 of said bore, a conventionalgas charging valve 28 being removably secured in said outer bore portion27.

The periphery of said closure head at its outer surface is beveled as at31 and the inner surface of the outer end or mouth 32 of said container11 has a corresponding bevel 33. The two beveled surfaces 31 and 33 whenthe closure head is positioned in the mouth 32 of the container thusform a V groove 34 shown in FIG. 2.

Positioned in the container 11 is a deformable partition, illustrativelyin the form of an elongated bladder 35 of rubber or similar materialhaving like characteristics. The bladder 35 is closed at one end as at36 and such closed end 36 has secured thereon hereon and preferablymolded integral therewith a rigid button or valve member 37 which isaxially aligned with the bladder and designed to move against the valveseat 19 when the bladder is expanded to close the port 18.

The mouth 38 of the bladder 35 has a thickened rim 39 to which anannular supporting member 41 is affixed by being bonded thereto heretoor molded therein as illustratively shown. The supporting member or ring41 is of relatively thin resilient sheet metal such as sheet steel andhas a curved lower or mounting portion 42 convex on its outer surface asat 43 and an upper or retaining portion 44.

The lower portion 42 is molded integrally into the thickened rim 39 ofthe bladder 35 with the upper portion 44 being transversely spacedoutwardly from the lower portion 42 to define an annular seatingshoulder 45.

Inasmuch as it is costly to hold diametrical tolerances on deep drawnlow cost shells as well as on metallic rings, the upper portion 44 ofthe supporting member 41 initially tapers outwardly slightly as shown inFIG. 3 so that the outer diameter of its free edge 46 is just slightlygreater than the inner diameter of the container 11 adjacent the mouththereof and below the beveled surface 33. Thus, when such upper portionis forced into the mouth 32 of the container it will readily fit thereinwith a snug fit.

The supporting ring is forced into the container mouth to an extent suchthat the upper or outer edge portion 46 of the supporting member willprotrude outwardly slightly beyond the lower end 47 of the beveledsurface 33 as is shown in FIG. 2. Due to the slight outward taper of theupper portion 44 of the supporting member, its outer surface will presssnugly against the inner surface of the container just slightly belowthe lower end 47 of beveled surface 33, without any discontinuities orgaps.

As shown in FIG. 1, the closure member 21 is positioned in thesubstantially cylindrical upper portion 44 of the supporting member withthe peripheral rim 23 of the closure member resting against locatingshoulder 45 of the supporting member. In such position, the top surface21' of the closure member is substantially flush with the mouth 32 ofthe container and the beveled surface 31 of the closure member isaligned with the beveled surface 33-of the container to define such Vgroove 34. The upper edge 46 of the supporting member will thus protrudeupwardly into the groove 34 beyond the apex thereof.

Preferably the closure member 21 fits relatively loosely in thesupporting ring to insure that the peripheral rim 23 of the closuremember will rest on the locating shoulder 45 in order that the upperportion 46 of the supporting ring will protrude freely into V groove 34.

outer edge of peripheral rim 23 and the outer surface 21' of the closuremember must be greater than the distance d" between the locatingshoulder 45 to the outer edge 46 of supporting ring 41 to insure thatthe outer edge portion protrudes into V groove 34.

In order to provide a dependable gas and liquid seal, a weld 55 isformed in the V groove 34 which will securely join the opposed beveledsurfaces 31, 33 as well as the protruding portion 46 of the supportingring 41 together. 1

It is apparent that when rubber is bonded to steel member such as therim 39 of the bladder to the lower portion 42 of the supporting member41, the introduction of heat resulting from welding, brazing or fusingcan readily be transferred through the heat conductible steel supportingmember 41 to the area where the rubber is bonded to the lower portion 42of the supporting member 41, and such heat if excessive, would destroythe bond.

. By reason of the construction which is the subject of this invention,the transmission of heat to the bond of the rim of the bladder to thelower portion 42 of the supporting member 41 is minimized.

' Thus, in the first instance the region where the bond is formed (i.e.in the annular groove 34) is remote from the bonded region of the rim 39to the lower portion 42.

Furthermore, a relatively large mass of metal is provided between thebonding region defined by the groove 34, and the rim 39 of the bladder.More particularly, this mass of material is provided by the cover member21 and the wall of the container 11, these members functioning as a heatsink to disperse the heat engendered by the welding action in theannular groove 34.

In addition, it is to be noted that the peripheral rim 23 of the covermember rests on the annular supporting surface 45 of the supportingmember so there either is no contact or only a minimum contact betweenthe peripheral rim of the cover member and the rim 39 of the bladder tominimize the transfer of heat.

Moreover, it is to be noted that due to the fact that the lower mountingportion 42 of the supporting member is inwardly displaced, the rim 39 ofthe bladder as well as the wall portion thereof will be spaced from thecontainer wall again to minimize heat transfer.

Due to the fact that the free edge 46 of the supporting member protrudesinto the annular groove, the weld performed in such annular groove willdependably connect such free'edge with the sides of the annular groovedefined by the beveled surfaces 31 and 33 to insure that an absolute gasand liquid tight seal will be formed.

If the free edge 46 should be below the apex of the groove, the weldjoint might not positively engage such free edge so that an absoluteseal might not be formed.

By reason of the configuration provided whereby the peripheral rim willseat on the annular supporting surface, the parts are properly locatedto insure that a dependable seal will be formed.

In addition to the foregoing, since the weld is performed at the top ofthe pressure vessel, a more dependable weld will be achieved than wouldbe accoml' d' thew ldw a the s'de ofthe res e l. p l h is i s due to theact that the m etai ifill w downwardly and more uniformly into crevicesthat ex ist. As a result of this feature, the welding action may beperformed with the pressure vessel in upright position without need torotate the pressure vessel in a jig but it is merely necessary for thewelder to move his welding torch around the top of the pressure vessel.

Furthermore, by reason of the construction above described, there is nopossibility of burn-through or melting of the supporting member whichmight cause portions of the latter to fall into the bladder and burn thesame, and furthermore, metal particles falling into the pressure vesselcould cause serious damage to pumps, gauges and the like, used in thehydraulic system in which the pressure vessel is incorportated.

By reason of the fact that the weld is preformed in a V-groove which issubstantially closed at its apex, the possibility of dislodgement ofparticles into the pressure vessel is substantially precluded.

In addition, the mechanical seal formed by the engagement of the twoedges of the beveled surfaces of the container and the cover memberagainst the protruding free edge of the supporting member prevents anycracks or crevices being formed.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

l. A pressure vessel comprising an elongated container of rigidmaterial, having one end open and the other end closed, said closed endhaving an axial port therethrough, a deformable bladder of resilientmaterial in said container, said bladder having a mouth at one end, andbeing closed at its other end, an annular sup porting member ofrelatively thin material bonded to the mouth of said bladder and havinga retaining portion extending outwardly therefrom, a cylindrical covermember positioned in the annular retaining portion, said cover memberand its encompassing supporting member being positioned in the mouth ofsaid con tainer, the opposed surfaces of said cover member and the mouthof said container adjacent the outer ends thereof being beveled todefine an annular groove therebetween that is substantially V-shaped incross section having its apex directed downwardly, with the free edge ofsaid retaining portion protruding slightly through said apex into saidannular groove, and weld means bonding the opposed beveled surfaces ofsaid I groove in said cover member and said container and opposedsurfaces of the protruding portion of said supporting member, to form adependable gas and liquid seal said bladder having a thickened rimportion at its mouth, said annular supporting member having a mountingportion bonded in the thickened rim portion, said retaining portionbeing transversely spaced radially outwardly from said mounting portionto define an annular seating shoulder, said cover member having arelatively narrow peripheral rim on its inner surface resting on saidseating shoulder between the thickened rim portion of said bladder andthe retaining portion of said supporting member, the lower ends of thebeveled surface of said container mouth and said cover member beingaligned when the peripheral rim of said cover member is seated on saidannular sealing shoulder.

1. A pressure vessel comprising an elongated container of rigidmaterial, having one end open and the other end closed, said closed endhaving an axial port therethrough, a deformable bladder of resilientmaterial in said container, said bladder having a mouth at one end, andbeing closed at its other end, an annular supporting member ofrelatively thin material bonded to the mouth of said bladder and havinga retaining portion extending outwardly therefrom, a cylindrical covermember positioned in the annular retaining portion, said cover memberand its encompassing supporting member being positioned in the mouth ofsaid container, the opposed surfaces of said cover member and the mouthof said container adjacent the outer ends thereof being beveled todefine an annular groove therebetween that is substantially V-shaped incross section having its apex directed downwardly, with the free edge ofsaid retaining portion protruding slightly through said apex into saidannular groove, and weld means bonding the opposed beveled surfaces ofsaid groove in said cover member and said container and opposed surfacesof the protruding portion of said supporting member, to form adependable gas and liquid seal said bladder having a thickened rimportion at its mouth, said annular supporting member having a mountingportion bonded in the thickened rim portion, said retaining portionbeing transversely spaced radially outwardly from said mounting portionto define an annular seating shoulder, said cover member having arelatively narrow peripheral rim on its inner surface resting on saidseating shoulder between the thickened rim portion of said bladder andthe retaining portion of said supporting member, the lower ends of thebeveled surface of said container mouth and said cover member beingaligned when the peripheral rim of said cover member is seated on saidannular sealing shoulder.